At home I use Debian GNU/Linux exclusively. With just a tiling window manager (i3 or sway). I have toyed with other stuff:
I absolutely need to have emacs and bash running, everything else is a second thought.
At dayjob I have to deal with windows10 and I hate it. But then --- right after DOS I went for IBM mainframes and DEC/VMS equipment, several Unix flavours. I sort of skipped Windows. I never got the hang of it and I honestly don't miss it.
Honestly, both OpenBSD and Genode seem like academic solutions looking for real-world problems. For non-desktop deployments, Linux seems to be the clear winner.
What can you do with OpenBSD and Genode that you can't do with Linux (in real-world applications)?
Alpine is certainly a nice base for Docker images.
I'm jealous of your time with VMS, but at the end of the day, operating systems are tools, not toys.
My too on the IBM mainframes, veritable eons ago. Thinking about it has me wanting to look up pictures of ISPF/PDF screens on MVS/TSO, and CMS (?) on VM.